Comprehensive power management scheme for the intelligent operation of photovoltaic‐battery based hybrid microgrid system

Abstract

This study proposes a comprehensive power management scheme (CPMS) for the economical and smart operation of a photovoltaic (PV) battery based Hybrid Microgrid (HMG) system. The solar-PV, DC-loads and battery storage are interfaced to DC-bus of the HMG. The battery is integrated into the DC-bus using a bidirectional energy storage converter (BESC). The voltage and frequency of AC-bus are regulated by utility grid and bidirectional interlinking converter (BIC) during grid-connected and islanded modes of operation, respectively. The proposed CPMS obviates high-speed communication link between converters for maintaining the system stability during power disturbances. Therefore, the vulnerability to collapse due to communication link failure is eliminated, thereby enhancing system reliability. The operational performance of HMG is improved with the proposed CPMS by providing additional features (minimisation of operating cost of the HMG, enhancement in voltage regulation of the DC-bus etc.) using low-speed communication network. The proposed CPMS can also be extended to a larger HMG system by utilising the full bandwidth of the communication network. Further, the proposed CPMS enables HMG to seamlessly switch from grid-connected to islanded mode and vice-versa. Experimental results validating the efficacy of the proposed CPMS are presented.